The process of transforming a 17-keto steroid to the corresponding steroid with an aldehyde at C.sub.17 by addition of a carbon atom is known to those skilled in the art. See, for example, C. Byon et al. in J. Org. Chem. 45, 4404 (1980) and references therein; Chem. Abst. 85, 124237g; and East German Pat. No. 117,673.
Aldehydes can be transformed to the corresponding difluoromethyl compound by reaction with selenium tetrafluoride, see Olah et al., J. Am. Chem. Soc. 96, 925 (1974), with sulfur tetrafluoride, see Martin and Kagan, J. Org. Chem. 27, 3164 (1962), or with diethylaminosulfur trifluoride, see Fieser and Fieser, Reagents for Organic Synthesis, Wiley Interscience, Vol. 6, p. 183 and Vol. 8, p. 166.
17,17-Difluoroandrost-4-en-3-one and 20,20-difluoroprogesterone are known, see Martin, supra. The 20,20-difluoromethylprogesterone of Martin was disclosed to possess central nervous system depressant activity which made the agents useful as sedatives and general anesthetics in mammals. U.S. Pat. No. 3,211,723 discloses that 20,20-difluoropregnane-11-one exhibits activity as an anti-fertility agent and can be used in controlling fertility in ovulating mammals and birds, for example, in animals such as swine, cattle, horses, sheep, dogs, cats and the like.
6.alpha.-Difluoromethyl corticoids are known, see Martin and Pike, J. Org. Chem. 27, 4086 (1962). 6,6-Difluoro-17.alpha.-acetoxyprogesterone is known, see G. A. Boswell, J. Org. Chem. 31, 991 (1966). However, Fried and Edwards in Organic Reactions in Steroid Chemistry, Van Nostrand, 1972, in Volume 1, devote Chapter 8 to Introduction of Fluorine Into The Steroid System. In 65 pages of discussion of fluorinated steroids, trifluoromethyl steroids were mentioned (p. 470) and the difluoromethylene steroids in the Martin et al. publications were discussed. Difluoromethyl steroids were not discussed.